A TOPSIS-Based Vulnerability Assessment Method of Distribution Network Considering Network Topology and Operation Status

Vulnerability assessment is one of the effective ways to prevent cascading failures of a distribution network (DN). Considering topological structure and operation status, a comprehensive assessment method based on the technique for order preference by similarity to ideal solution (TOPSIS) is proposed to accurately identify the vulnerable parts of the DN. In the method, the improved structural vulnerability indices based on complex network theory are defined, such as degree and network efficiency. And the electrical betweenness and power flow transfer entropy are established to evaluate the state vulnerability of a DN. Combining the analytic hierarchy process (AHP) and the entropy weight method, a comprehensive weight matrix of each vulnerability index is obtained. Based on the weighted vulnerability indices, the TOPSIS method is proposed to calculate the comprehensive vulnerability of each node and line in the DN. Moreover, the obtained comprehensive vulnerability results are corrected by the grey correlation degree to accurately identify vulnerable parts in the DN. In addition, the system transmission efficiency index is established to describe the degree of system performance degradation of the DN under different attack strategies. The simulation results of IEEE 33-bus test case show that the proposed method can effectively identify vulnerable nodes and lines in the DN.